AXI JESD204B HDL

AXI JESD204B HDL Linux Driver.

Warning

This driver is RETIRED, DEPRECATED and not used anymore in any of the recent projects!

Please see here instead:

• AXI JESD204 TX

• AXI JESD204B RX

Supported Devices

1. deprecated

Description

The AXI JESD204 HDL driver is the driver for the HDL interface core which is used on various FPGA designs interfacing to the AD9250. The driver is implemented as an Open Firmware Device Tree (DT) platform driver. It’s register map can be found here: Register access

Source Code

Status

Source	Mainlined?
drivers/iio/jesd204/axi_jesd204b_v51.c	WIP

Files

Function	File
driver	drivers/iio/jesd204/axi_jesd204b_v51.c
include	drivers/iio/jesd204/axi_jesd204b_v51.h

Example platform device initialization

The AXI JESD204B driver is a platform driver and can currently only be instantiated via device tree.

Required devicetree properties:

• compatible: Should always be *xlnx,axi-jesd204b-rx2-1.00.a* or *xlnx,axi-jesd204b-rx4-1.00.a*

• reg: Base address and register area size. This parameter expects a register range.

• clocks: Clock provider phandle

• clock-name: Clock input name string

• jesd,frames-per-multiframe: Number of frames per multi-frame

• jesd,bytes-per-frame: Number of bytes (octets) per frame

• jesd,lanesync_en: Enable lane synchronization

• jesd,scramble_en: Enable scrambling

Example:

axi_jesd204b_rx2_0: axi-jesd204b-rx2@77a00000 {
    compatible = "xlnx,axi-jesd204b-rx2-1.00.a";
    reg = < 0x77a00000 0x10000 >;
    clocks = <&ad9250_clkin>;
    clock-names = "clkin";
    jesd,lanesync_en;
    jesd,scramble_en;
    jesd,frames-per-multiframe = <32>;
    jesd,bytes-per-frame = <2>;
    xlnx,cf-buftype = <0x0>;
    xlnx,dphase-timeout = <0x8>;
    xlnx,family = "kintex7";
    xlnx,num-mem = <0x1>;
    xlnx,num-reg = <0x1>;
    xlnx,s-axi-min-size = <0x1ff>;
    xlnx,slv-awidth = <0x20>;
    xlnx,slv-dwidth = <0x20>;
    xlnx,use-wstrb = <0x0>;
} ;

Enabling Linux driver support

Configure kernel with make menuconfig (alternatively use make xconfig or make qconfig)

Adding Linux driver support

Configure kernel with make menuconfig (alternatively use make xconfig or make qconfig)

Linux Kernel Configuration
    Device Drivers  --->
    <*>     Industrial I/O support --->
        --- Industrial I/O support
        -*-   Enable ring buffer support within IIO
        -*-     Industrial I/O lock free software ring
        -*-   Enable triggered sampling support

              *** Analog to digital converters ***
        [--snip--]

        <*>   Generic AXI JESD204B configuration driver

        [--snip--]

Driver Testing

# cd /sys/bus/platform/devices/44a91000.jesd204/
# ls -al
total 0
drwxr-xr-x    2 root     root             0 Jan  1 00:21 .
drwxr-xr-x   25 root     root             0 Jan  1 00:00 ..
lrwxrwxrwx    1 root     root             0 Jan  1 00:21 driver -> ../../../bus/platform/drivers/cf_axi_jesd204b_v51
-rw-r--r--    1 root     root          4096 Jan  1 00:21 driver_override
-r--------    1 root     root          4096 Jan  1 00:21 lane0_info
-r--------    1 root     root          4096 Jan  1 00:21 lane0_syncstat
-r--------    1 root     root          4096 Jan  1 00:21 lane1_info
-r--------    1 root     root          4096 Jan  1 00:21 lane1_syncstat
-r--------    1 root     root          4096 Jan  1 00:21 lane2_info
-r--------    1 root     root          4096 Jan  1 00:21 lane2_syncstat
-r--------    1 root     root          4096 Jan  1 00:21 lane3_info
-r--------    1 root     root          4096 Jan  1 00:21 lane3_syncstat
-r--r--r--    1 root     root          4096 Jan  1 00:21 modalias
-rw-------    1 root     root          4096 Jan  1 00:21 reg_access
lrwxrwxrwx    1 root     root             0 Jan  1 00:21 subsystem -> ../../../bus/platform
-rw-r--r--    1 root     root          4096 Jan  1 00:21 uevent

# cat lane0_info
DID: 0, BID: 1, LID: 1, L: 4, SCR: 1, F: 1
K: 32, M: 2, N: 14, CS: 0, S: 1, N': 16, HD: 1
FCHK: 0x81, CF: 0
ADJCNT: 0, PHYADJ: 0, ADJDIR: 0, JESDV: 1, SUBCLASS: 1
MFCNT : 0x0
ILACNT: 0x0
ERRCNT: 0x0
BUFCNT: 0x14
LECNT: 0x0
FC: 500000000
#
# cat lane0_syncstat
NOT_IN_TAB: 0, DISPARITY: 0, UNEXPECTED_K: 0
#